{"id":12903,"date":"2020-08-25T09:15:33","date_gmt":"2020-08-25T15:15:33","guid":{"rendered":"https:\/\/www.coloradofloodthreat.com\/?p=12903"},"modified":"2020-08-26T07:20:40","modified_gmt":"2020-08-26T13:20:40","slug":"ftb-08-25-2020-increase-in-afternoon-storm-coverage-over-the-mountains","status":"publish","type":"post","link":"https:\/\/archive-coftb.dewberryanalytics.com\/?p=12903","title":{"rendered":"FTB 08-25-2020: Increase in Afternoon Storm Coverage Over the Mountains"},"content":{"rendered":"<p>Issue Date: Tuesday, August 25th, 2020<br>\nIssue Time: 9:15AM MDT<\/p>\n<p><em>&mdash; A <strong>LOW<\/strong> flood threat has been issued for the Spring Creek burn area<\/em><\/p>\n<p>Today the pattern begins to shift slightly as some mid-level energy, associated with an incoming <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;trough&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;An elongated area of relatively low atmospheric pressure; the opposite of a ridge.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>trough<\/span> and remnants of Genevieve, start to move eastward. As these shortwaves move inland (area of cloud cover below), they should displace the ridge axis slightly eastward, which will start to pull some mid and upper level moisture into the state from the east (green oval). This means that rainfall efficiencies and coverage should start to increase with another round of <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;scattered&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;25-40% areal coverage&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>scattered<\/span> afternoon storms forecast over the mountains and western plateaus. The High itself doesn&rsquo;t get displaced much, so expecting steering winds to be on the lower end again with the pop-like <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;convection&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;Refers to vertical atmospheric motion driven by buoyancy, i.e., warm air is less dense than cool air, and therefore rises. One of the primary drivers of thunderstorm development, especially during monsoon season.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>convection<\/span> that forms over the higher terrains. <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;CAPE&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;(Stands for: Convective Available Potential Energy) CAPE is a measure of the amount of available energy in the atmosphere for convection. Higher values indicate a greater potential for stronger updrafts, thus an increase in the potential for thunderstorms and severe weather.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>CAPE<\/span> also looks like it will increase when compared to yesterday, so there&rsquo;s a better chance for some thunderstorms this afternoon over the mountains. While thunderstorms typically mean more wetting rainfall, some gusty <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;outflow&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;A cool pool of air that results when a thunderstorm downdraft reaches the surface and spreads horizontally.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>outflow<\/span> winds should also be expected (up to 40 mph) with the large <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;dew point&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;The temperature to which a given air parcel must be cooled (at constant pressure and water vapor content) in order for saturation to occur.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>dew point<\/span> depressions along with lightning.<\/p>\n<p><img loading=\"lazy\" class=\"size-full wp-image-12904 aligncenter\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2020\/08\/vis_20200825.png\" alt=\"\" width=\"541\" height=\"491\" srcset=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2020\/08\/vis_20200825.png 541w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2020\/08\/vis_20200825-300x272.png 300w\" sizes=\"(max-width: 541px) 100vw, 541px\"\/><\/p>\n<p>There will be a slightly greater <span class=\"glossaryLink\"  aria-describedby=\"tt\"  data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;PW&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;(Stands for: Precipitable Water) The total atmospheric water vapor contained in a vertical column of the atmosphere. It is typically measured in inches, and anomalously (deviation from normal) high values of precipitable water generally correlate to heavy rainfall potential.&lt;\/div&gt;\"  data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>PW<\/span> surge over the southwest corner of the state as the High become oriented SW to NE, so expecting some higher totals in this area as well as over the southern Southeast Mountains. With higher totals and chances for precipitation forecast over the Southeast Mountains and Raton Ridge intersect, a thunderstorm could pop over the southern end of the Spring Creek burn area. A Low flood threat has been issued with <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;isolated&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;less than 10% areal coverage&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>isolated<\/span> rain totals up to 0.70 inches possible, which could trigger some <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;flash flooding&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;&amp;lt;!-- wp:paragraph {&amp;quot;textColor&amp;quot;:&amp;quot;white&amp;quot;} --&amp;gt;\n&amp;lt;p class=&amp;quot;has-white-color has-text-color&amp;quot;&amp;gt;flash flooding can refer to usually dry areas becoming rapidly inundated with water, or rapid water level rises on streams, creeks, or rivers beyond flood stage; typically caused by heavy rainfall, but can also be caused by meltwater&amp;lt;\/p&amp;gt;\n&amp;lt;!-- \/wp:paragraph --&amp;gt;&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>flash flooding<\/span> and mud\/debris flows onto Highway 12 if a storm forms overhead. Elsewhere, the rainfall should be gradual enough and heavier rainfall cores small enough that flooding is not expected.<\/p>\n<p>Over the plains, a lee <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;trough&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;An elongated area of relatively low atmospheric pressure; the opposite of a ridge.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>trough<\/span> may produce a storm or two over the Northeast Plains if storms can break the <span class=\"glossaryLink\"  aria-describedby=\"tt\"  data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;cap&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;The area where a parcel of air has negative buoyancy or sinks. The intensity of the cap is measured by its convective inhibition. If the cap is sufficiently large, it may prevent thunderstorms from forming at all.&lt;\/div&gt;\"  data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>cap<\/span>. I would say the chances of this occurring are a little greater than the last couple of days with the extra mid-level lift moving into the area. Additionally, some storms could fire over the Cheyenne Ridge and move southeast across the border. Overall, storms should be on the weaker end, so flooding is not forecast.<\/p>\n<h3><strong>Today&rsquo;s Flood Threat Map<\/strong><\/h3>\n<p>For more information on today&rsquo;s flood threat, see the map below. If there is a threat, hover over the threat areas for more details, and click on burn areas to learn more about them. For Zone-Specific forecasts, scroll below the threat map.<\/p>\n<p><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2020\/08\/FTB_20200825_snap.png\"><img loading=\"lazy\" class=\"aligncenter wp-image-12914\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2020\/08\/FTB_20200825_snap.png\" alt=\"\" width=\"880\" height=\"616\" srcset=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2020\/08\/FTB_20200825_snap.png 880w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2020\/08\/FTB_20200825_snap-300x210.png 300w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2020\/08\/FTB_20200825_snap-768x538.png 768w\" sizes=\"(max-width: 880px) 100vw, 880px\"\/><\/a><\/p>\n<h3><strong>Zone-Specific Forecasts:<\/strong><\/h3>\n<h4><strong>Northern Mountains, Central Mountains, San Juan Mountains, Grand Valley, Southwest Slope, <\/strong><strong>San Luis Valley, <\/strong><strong>&amp; Northwest Slope: <\/strong><\/h4>\n<p>Increasing coverage of afternoon storms is expected over the mountains as well as the plateaus with some thunderstorms possible. It will likely be too dry to get much, if any, rainfall over the lower elevations, but the increased cloud cover should help a little with the heat. <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;isolated&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;less than 10% areal coverage&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>Isolated<\/span> totals up to 0.2 inches (north), 0.5 inches (central), and 0.75 inches (south) will be possible by morning. Due to the large <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;dew point&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;The temperature to which a given air parcel must be cooled (at constant pressure and water vapor content) in order for saturation to occur.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>dew point<\/span> depression and high <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;DCAPE&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;(Stands for: Downdraft Convective Available Potential Energy) DCAPE is a measure of the potential strength of rain-cooled downdrafts within deep convection. Larger values indicate a greater potential for stronger downdrafts, thus an increase in the potential for strong wind gusts.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>DCAPE<\/span> values, some strong <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;outflow&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;A cool pool of air that results when a thunderstorm downdraft reaches the surface and spreads horizontally.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>outflow<\/span> winds (up to 40 mph) will be possible along with lightning. Small hail may be possible with thunderstorms that form further south. Smoke will hang around with the lowest visibility expected over the Northwest Slope and Northern Mountains. Some lingering (light) precipitation is likely overnight as a second <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;shortwave&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;A disturbance in the mid or upper part of the atmosphere which induces upward motion ahead of it.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>shortwave<\/span> moves in from the west.<\/p>\n<p>Primetime: 1PM to 3AM<strong>&nbsp;<\/strong><\/p>\n<h4><strong>Southeast Mountains, <\/strong><strong>F<\/strong><strong>ront Range, Palmer Ridge, Raton Ridge, Urban Corridor, Southeast Plains, &amp; Northeast Plains:<\/strong><\/h4>\n<p>Coverage of storms over the eastern mountains should increase this afternoon with max 1-hour rain rates up to 0.5 inches (north) and 0.75 inches (south) possible. Along with rainfall, gusty <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;outflow&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;A cool pool of air that results when a thunderstorm downdraft reaches the surface and spreads horizontally.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>outflow<\/span> winds and dangerous lightning are forecast. A Low flood threat has been issued for the Spring Creek burn area as chances increase for a storm forming over the southern end of the scar. The slow steering winds could also be an issue if a storm forms overhead.<\/p>\n<p>As storms move off the mountains, the best chance for survival will be over the ridges with totals up to 0.3 inches possible. Additional storms may fire over the Northeast Plains either along a line of convergence (lee <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;trough&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;An elongated area of relatively low atmospheric pressure; the opposite of a ridge.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>trough<\/span>) or travel southeast from the Cheyenne Ridge. Max 1-hour rain rates up to 0.70 (east) will be possible, so flooding is not expected. Expect another day of hot temperatures all around.<\/p>\n<p>Primetime: 12:30PM to Midnight<\/p>","protected":false},"excerpt":{"rendered":"<p>Issue Date: Tuesday, August 25th, 2020 Issue Time: 9:15AM MDT &mdash; A LOW flood threat has been issued for the Spring Creek burn area Today the pattern begins to shift slightly as some mid-level energy, associated with an incoming <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;trough&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;An elongated area of relatively low atmospheric pressure; the opposite of a ridge.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>trough<\/span> and remnants of Genevieve, start to move eastward. As these shortwaves move inland (area of [&hellip;]<\/p>","protected":false},"author":8,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[6],"tags":[],"post_mailing_queue_ids":[],"_links":{"self":[{"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/12903"}],"collection":[{"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=12903"}],"version-history":[{"count":6,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/12903\/revisions"}],"predecessor-version":[{"id":12915,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/12903\/revisions\/12915"}],"wp:attachment":[{"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=12903"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=12903"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=12903"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}